One form of electrical connector includes a plug and a receptacle. Each of the plug and receptacle portions includes an insulative insert carrying one or more electrical contacts. When the plug and receptacle are mated, the electrical contacts are engaged to complete an electrical circuit.
Connector parts, such as plugs and receptacles, can advantageously be made of a large variety of materials. Metal bodies have been used, but, because of their tendency to corrosion, it is often necessary to add expensive and wear-sensitive corrosion-inhibiting plating. More recently, the corrosion problem has been overcome by the use of composite or plastic materials for plug and receptacle bodies.
Both bayonet and threaded coupling means have been used for facilitating maintenance of the engagement between the plug and the receptacle. Where a threaded engagement means is used, the plug comprises a cylindrical plug body member. The receptacle, generally tubular in shape, has a matching set of threads which are inscribed about its outer diameter.
One problem with plug/receptacle electrical connectors is their susceptibility to inadvertent disconnection or decoupling as a result of shock or vibration. While threaded couplings have generally been superior to bayonet couplings in reducing inadvertent vibration-caused disconnection, threaded couplings can, over time, also loosen or become completely disconnected in the presence of shock or vibration. Such considerations are of considerable importance in situations in and near heavy machinery, vehicles, planes and ships, such as encountered in military applications.
Several types of detent mechanisms have been provided in order to inhibit inadvertent decoupling of electrical connectors due to shock or vibration. These devices, however, have been relatively complicated, required a large number of separate components and are often disposed inside the connector bodies, requiring intricate assembly operations.
In order to simplify construction of detent structures for resisting inadvertent decoupling, one technique has been to machine, or "broach" ratchet parts, such as teeth, about interior surfaces of plug or receptacle bodies, thus arriving at a structure wherein the ratchet or detent teeth are integral with the connector part itself. The use of composite parts, or plated metal parts, however, does not lend itself well to this manufacturing technique, which is itself complex and intricate. Composite materials, for example, do not possess sufficient hardness and resistance to mechanical wear and abrasion to permit the integral formation therein of detent parts such as teeth, leaf springs and the like. The alternative is that, where composite materials are used for connector part bodies it is not usually practical to form detent teeth or other parts integrally with the connector bodies. In such instances, it becomes necessary to assemble such detent parts of other, harder materials within the connector structure itself.
Where threaded electrical connectors are involved, a typical requirement is that the coupling, and its associated detent, or decoupling inhibiting mechanism, be capable of withstanding at least 500 couple/uncouple cycles. Thus, while the structure must be capable of resisting vibratory or shock forces tending to unscrew the connector parts, it must not entirely prevent such releasing movement either.
It is a general object of the present invention to provide a ratchet structure for inhibiting inadvertent disconnection between connector parts without the need to broach for machine ratchet teeth integrally to connector body parts, and to provide such ratchet structure which can be used in connector parts made from virtually any material or composite while maintaining improved ratchet force and wear characteristics.